Method of adding a casing to a refractory article



y 7, 1964 c. B. REYNOLDS ETAL 25,615

METHOD OF ADDING A CASING TO A REFRACTORY ARTICLE Original Filed Nov.15, 1957 3 Sheets-Sheet 1 F 4 INVENTORS I Charles B Reynolds Donald C.Burklo BY Waher M. Eklund Attorney TICLE y 7, 1964 c. B. REYNOLDS ETALMETHOD OF ADDING A CASING TO A REFRACTORY AR 3 Sheets-Sheet 2 OriginalFiled Nov. 15, 1957 urklo BY Walter MEkIund Attorney 6 July 7, 1964 C.B. REYNOLDS ETAL METHOD OF ADDING A CASING TO A REFRACTORY ARTICLEOriginal Filed Nov. 15, 1957 3 Sheets-Sheet 3 INVENTORS Charles B. Renolds Donald C Bur to Walter M. Eklund Afforney United States Patent OfiRe. 25,615 Reissued July 7, 1964 ice 25,615 METHOD OF ADDING A CASING TOA REFRACTORY ARTICLE Charles B. Reynolds, Saratoga, Calif, and Walter M.Ekluud and Donald C. Burklo, Columbiana, Ohio, asslgnors to KaiserAluminum & Chemical Corporation, Qakland, Califi, a corporation ofDelaware Original No. 3,083,453, dated Apr. 2, 1963, Ser. No. 696,771,Nov. 15, 1957. Application for reissue May 27, 1963, Ser. No. 284,290

17 Claims. (Cl. 29-4705) Matter enclosed in heavy brackets appears inthe original patent but forms no part of this reissue specification;matter printed in italics indicates the additions made by reissue.

This invention relates to a method for plating a preformed refractorybrick or block whereby the metal plate is firmly attached to therefractory to withstand subsequent handling.

Metal-encased refractory articles have long been known in theconstruction of industrial furnaces; and many methods have been proposedand used for making these articles. However, it has been a difiiculty ofthe prior art that the refractory brick or block has not been safelyheld by the metal cases, and sometimes the brick fall out of the casesduring handling and especially during installation in furnaces, so thatthe bricks themselves may be broken or often cause serious injury to theworkers. Another disadvantage of the prior art has been that in somemethods of proceeding the case could only be applied as the refractoryarticle was being formed and was not therefore applicable to a burnedbrick.

It is an object of the present invention to provide a metal-casedrefractory article wherein the metal case tightly and securely engagesthe refractory component. It is a further particular object of thepresent invention to provide a method of applying a metal casing to apreformed refractory brick, which can be burned or un burned, in amanner to insure secure adhesion of the casing to the brick duringsubsequent handling and installation.

According to this invention, there is provided a unitary refractoryarticle comprising a refractory block and a metal casing disposed aboutthe block, the casing comprising a plate of metal which is locallydeformed to fit into and conform with shallow, discontinuous depressionsof the longitudinal face of the refractory object and securely andtightly engages such refractory. Preferably, the casing is of iron orsteel for most industrial uses, but, if desired, other metal plates canbe employed, for example, nickel or aluminum'plate is sometimes useful.The refractory block is provided with one or more shallow discontinuousdepressions in a side face thereof, and the metal plate is placed on theblock and is then deformed to fit into and conform with suchdepressions.

The invention and its mode of operation are further illustrated by theaccompanying drawings, wherein:

FIGURE 1 is a perspective view of a refractory block having preformeddepressions therein useful in making up the article according to thepresent invention; I

FIGURE 2 is a perspective view of one embodiment of c this inventionshowing one shallow depression in one longitudinal side and a caseapplied thereover;

FIGURE 3 is a perspective view of a plated article according to thepresent invention comprising the refractory block and a U-shaped case;

FIGURE 4 is a perspective view of another article made according to thepresent invention, including two U-shaped plates;

FIGURE 5 is a perspective view of another embodiment of the presentinvention, comprising a refractory block and a U-shaped plate whereofthe side arms cover at least a major portion of a side of the block;

FIGURE 6 is a perspective view of still another and particularlyadvantageous embodiment of the present invention;

FIGURE 7 is a sectional view on the line 7, 7 of FIG- URE 6;

FIGURE 7a is a detailed view of the use of the metal button as shown inFIGURE 7;

FIGURE 8 is a perspective view of a hanger unit made according to thepresent invention;

FIGURE 9 is a perspective View of a hanger masonry unit composed of twoblocks and metal plated-according to the present invention;

FIGURE 10 is a perspective view of a pair of blocks showing a stillfurther embodiment of the present invention;

FIGURE 11 is a schematic arrangement for carrying out the process of thepresent invention;

FIGURE 12 shows schematically another arrangement for carrying out aspecific embodiment of the present invention.

According to the present invention, a refractory block, preferably anonacid or basic refractory, is preformed to the desired shape, andthere is provided in such block during formation at least one shallow,discontinuous depression. Alternatively, the block or brick is formed,for example in a brick press or in any desired manner, and afterhardening, the desired shallow discontinuous depression or depressionsare formed therein by drilling with a suitable drill. For instance, suchdepressions are formed by drilling with a hard drill, such as a tungstencarbide driil about one inch in diameter. Preferably, two or more suchdepressions are provided in one longitudinal face, and, if desired, oneor more or preferably two or more such shallow depressions are providedin two longitudinal faces; and in this type of structure the shallowdepressions are preferably in opposed faces.

It has been found, according to the invention, that it is possible tokey a plate onto a refractory brick using a shallow depression andthereby to obtain firm adhesion of the plate to the brick duringsubsequent handling. The depressions are discontinuous and shallowinorder to maintain the strength of the brick, and it has been foundlikewise that these discontinuous depressions enable keying of the plateto the brick in such a manner that the plate does not slip or slide orchange positions with respect to the refractory block which it coats orcontains. In general, these depressions do not exceed about inch indepth, and preferably are from about /2 to one inch in diameter. Thedepressions can be of any desired configuration, such as circular,square, V-shaped, diamond-shaped, hemispherical and the like.

The metal plate which is applied is preferably a U- shaped plate and ismade of any desired metal. The web of the U-shaped metal plate orchannel fits over one longitudinal face of the brick, and the arms ofthe plate extend over two adjacent side faces of the brick. In manyembodiments there may be employed two U-shaped casings, the side arms ofwhich will extend over approximately one-half a longitudinal face of thebrick, as illustrated for instance in FIGURE 6. However, in someinstances it is more convenient to plate the brick on three sides, andin such embodiment the side arms of the U-shaped plate may extend oversubstantially the entire adjacent side faces of the brick. Thedepressions can be placed toward the central areas of the side face, butit is usually preferred to place them at approximately the edges of theside arms of the plate Other than U-shaped cases are employed, ifdesired.

The invention is applicable in making metal plated single refractoryblocks, and it can also be employed in making hanger units which arecomposed of two refractory blocks placed side by side so as to form acommon hanger receiving socket, as will be further described below. Instill another mode of operation a U-shaped plate or a pair of U-shapedplates are applied to one-half only of a refractory block, whereby theremaining half, lengthwise, of the block remains unplated; and in suchembodiments when these blocks are placed in juxtaposition in a furnacewall, the metal plate of the one will complement the metal plate of thenext one, thereby providing only one thickness of metal between adjacentblocks in a wall.

The refractory block component is a formed shape composed of nonacid,that is neutral or basic, refractory material. It is, for example, madeof deadburned magnesite, alumina, periclase, chromite, magnesia-chromeor chrome-magnesia mixes or of any other desired neutral or basicrefractories; and the mixes are made up, bonded and formed into shape inthe manner known to the art. If desired, the formed shapes are burned,baked or fired prior to application of the metal encasement; but,alternatively, the metal casing can be applied to the unburned orchemically bonded shapes. As stated above, during formation the shapesare provided with the desired number of shallow, discontinuousdepressions in one or more longitudinal or side faces thereof, or,alternatively, the depressions as desired are drilled into the formedbrick. The ordinary straight brick or rectangular parallelepiped isshown, for instance, in most of the figures, but a wedge or key formwell known in this art can alternatively be employed as shown in FIG. 4.Also, a composite article is made up according to one embodiment,comprising two refractory blocks, disposed on end and side by side andencased in a pair of U-shaped casings keyed to the brick according tothe invention by deformation of the metal plate into the shallow,discontinuous depression in the side face of at least one of the bricks;and, if desired, a

metal spacer or divider plate is disposed between facing surfaces of thetwo blocks. This spacer or divider plate is made of any desiredmaterial, but most usually iron or steel is employed.

According to one mode of operating the method of the present invention,a basic or neutral refractory block is prepared with one or more shallowdepressions in one or more of the side faces of the block, as desired.The U-shaped casing is placed on the block in such manner that the webengages one longitudinal face, and the side arms extend over adjacentlongitudinal faces of the brick or block, and the edges of the side armsextend over or lie directly above the depressions in the block. Pressureis now applied to the edges or edge of the side arms to 'force the metalinto conformity with the depression in the block, and the case is thuskeyed to the block in a safe and secure manner. It is preferable that anedge of a side arm overlie two such depressions and be depressed intoconformity with the depressions in order to obtain more secureaflixation of the plate to the block, with less tendency of the plate tobe moved or skewed about with reference to the block.

In another mode of carrying out the process of this invention, a brickis provided with the shallow depressions as described above, and aU-shaped metal plate is placed on the block in such manner that the webengages one longitudinal side face and the side arms extend over and incontact with two adjacent side faces of the block. Preferably, twoshallow depressions underlie at least one of the side arms of the metalplate. The metal plate is now heated directly above the shallowdepressions and is pressed and deformed into conformity with the brickwhile being heated. The heating step increases the plasticity of themetal and facilitates its deformation into the depression. After themetal has been depressed into conformity with the depression in thebrick, heating is continued for a short time to relieve stresses in themetal. It is an advantage of this mode of operation that a thicker metalcan be employed and can be depressed with greater ease into thedepressions, with less chance of damage to the metal and to the brick.Furthermore, it enables depressing metal into the shallow depressions atany desired part of the metal case, whereas when the metal is deformedinto the depressions in the cold and without heating, it is preferred todo so at the edges of the U-shaped arms.

In a particular advantageous mode of operation a brick is provided withthe preformed shallow depressions as previously described, that is withone or more, preferably two, depressions in one or more side faces. Asmall metal piece, such as a metal button of any desired shape whichfits into the depression, is placed therein and then two U-shaped platesare placed on the brick in such manner that the edges of the side armsare disposed above, or approximately abut over, the metal buttons orpieces disposed within the recesses. Suitably, the metal button is apiece of metal, such as iron, steel, nickel or other desired metal, of ashape slightly smaller than but conforming to the shape of thedepression and wholly contained within the depression when placedtherein. If desired, the metal button or piece is held within the recessby a small amount of an adhesive such as a rubbery adhesive, or a glue.After the U-shaped cases are so placed that the edges of the side armsare disposed above the metal piece, welding heat is applied in suchmanner as to weld the cases together by means of the metal button, andsince the metal button is disposed within the brick recess, it anchorsthe cases to the brick very firmly and insures continued tightengagement between the case and the brick. Very good results. areobtained 'according to this mode of operation by providing a brickhaving two shallow recesses in one side face, placing a metal button ineach such shallow depression, placing the two U-shaped cases on thebrick whereby the edges of two side arms are disposed over the shallowdepressions and metal pieces, and welding the cases together through themetal button, the shallow depressions being disposed in a linesubstantially parallel with the longitudinal access of the brick. Ifdesired, however, one or more such shallow depressions can be disposedin opposing side faces of the brick, whereby they underlie both pairs ofedges of the side arms of the U-shaped cases. In still another method ofoperating according to this embodiment, the edges of the side arms canbe depressed into the preformed shallow depressions in the brick, asmall piece of metal laid into the depression in the metal case andheat, for example, welding heat, is then applied, whereby the metalbecomes plastic and flows or is deformed into the shallow depression,filling it and keying the case securely to the brick. Alternatively, twoor more L-shaped cases can be applied to the brick and affixed theretoin this manner, welding by means of metal buttons placed within theshallow depressions.

The invention will now be described with particular reference to theaccompanying drawings.

FIGURE 1 shows a masonry unit which is a magnesia refractory brick 10having a side face 11 in which are disposed two shallow depressions 12,which is suitable for encasement according to the present invention.

FIGURE 2 shows a basic refractorybrick 10 which is provided with ashallow depression 12 in side face 11 thereof, and having U-shaped metalcasing disposed over one side face and extending about half-way overeach of the two adjacent side faces of the brick, the edge 26 of casing13 passing over depression 12, and being depressed therein and intoconformity with the depression as at 16.

FIGURE 3 is another embodiment of the present invention in which 10 islikewise a basic brick provided with a U-shaped casing 13 coveringsubstantially half of the entire area of the side faces of the brick. Inthis embodiment there are provided two shallow depressions 12 in oneside face of the brick, and the edge of casing 13 is depressed intodepressions 12 as at 16, and in substantial conformity with the shape ofone-half of such depression which underlies the edge of case 13. This isa particularly advantageous embodiment in that the provision of twodepressions in one side face of the brick assists in preventing anytwisting with respect to the brick during subsequent handling.

IN FIGURE 4 is shown a brick which is likewise a basic brick but is ofwedge shape. Brick 10' carries two U-shaped casings 13 and 13, the edgesof which 26 and 26' lie adjacent each other and over shallow depressions12 in brick 10. Shallow depressions 12' of which there are likewise twoin number, are disposed on the opposing side face of brick 10' and theopposing edges of cases 13 and 13 lie adjacent each other overdepressions 12'. According to the present method, the casings 13 and 13'are depressed as at 16 and 16' into conformity with the shallowdepressions 12 and 12' in brick 10' and serve to key the casings to thebrick and in secure attachment thereto.

FIGURE 5 shows another embodiment of the present invention in which itis particularly advantageous to deform the metal into conformity withthe shallow depression in the brick with the use of heat. Basic brick 10is provided with U-shaped casing 14 of which the side arms are longenough to substantially cover the entire side 11 of brick 1t). Shallowdepressions 12 have been previously provided in the side face 11 bydrilling with a tungsten carbide drill, and heat and pressure areapplied to the metal casing in order to deform the casing at intoconformity with the shallow depressions 12, the

heating being continued to relieve stresses in the metal.

Heat, to deform the metal, can be applied in this manner in a simplefashion with the use of spot welding machine having water-cooled copperelectrodes about inch in diameter, maintaining the temperature belowthat which welding would occur.

In FIGURES 6, 7 and 7a there are shown views of a particularlyadvantageous method of encasing bricks as described herein. As anexample, basic brick 10 is provided with shallow hemisphericaldepressions 12, preferably two on one side face of the brick as shown inFIG- URE 6, and about inch in diameter, and preferably disposed at aboutthe central axis of side face 11 and parallel to a longitudinal axis ofthe brick. Metal pieces or buttons 17 which are suitably smaller thandepressions 12, but the diameters of which are greater than half thediameter of depression 12 so that they will underlie both edges of theU-shaped casings to be applied, are placed in de pressions 12. If thebrick is lying on its side so that depressions 12 are in the upper face,no precautions are needed to maintain buttons 17 in place, but,alternatively they can be afiixed in the depressions by a small amountof a suitable adhesive and then forwarded to the casing station. Casings13 and 13', of the ordinary U-shaped type, are then placed on brick 10so that their edges overlie buttons 17. Welding heat is then applied andthe case edges are depressed and are welded together through buttons 17.This embodiment is shown in cross-section in FIG. 7 which is taken online 7, 7 of FIG. 6 and shows in greater detail the disposition of thevarious elements. FIG. 7a is a detail showing the button 17 in adepression 12 of brick 10, and the overlying edges of cases 13 and 13'which are welded together as at 16, and are slightly depressed into thedepression during the welding operation. In any event, the provision ofthe button insures keying of the casing to the brick and insures thatthe casing will remain firmly attached to the brick during subsequenthandling and installation, while at the same time the brick is notweakened by a continuous groove or by a deep insertion into therefractory material itself.

As shown in FIGS. 8 and 9, the invention is also applicable in applyingcases to hanger units for use in refracit-O tory furnace roofs orfurnace roofs to be operated at high temperatures. In FIG. 8 a basicrefractory brick 10 is provided with a hanger-receiving or supportmeans-receiving socket generally indicated at 24, and is also providedwith two U-shaped cases 13 and 13', the edges of which overlie shallowdepressions 12 in brick 10 and are deformed into conformity therewith asindicated at v16. FIG. 9 shows a hanger unit comprising two refractoryblocks 18 and 18' which are provided with recesses which form a commonhanger-receiving socket, generally in dicated at 20, in the manner knownto this art. A metal plate 19 is disposed between the adjoining faces ofblocks 18 and 18'. Two U-shaped casings 21 and 22 are placed over thecombined unit and their edges are disposed over shallow depressions 12provided in block 18 The edges of casings 21 and 22 are, according tothe present invention, then depressed, into shallow depressions 12 asindicated at 16, and serve to key the casing to the brick and to insureits firm adherence thereto during subsequent handling and installation.It will be understood that to secure greater adherence of the casings tothe blocks, metal buttons can be placed in depressions 12 and weldingheat applied in the same manner as described with reference to FIGURE 6.

FIGURE 10 shows still another embodiment in which U-shaped cases 23 and23' are so applied to a brick 10 as to cover substantially one-half ofthe side faces thereof. The metal cases in this embodiment are alsodepressed as at 16 into conformity with a preformed shallow depression12 in brick 10 and are thereby keyed to brick 10. In this embodimentone-half of each brick 10 is metal plated or coated in this manner andwhen installed in a furnace, they are so juxtaposed as shown in FIG. 10that a single layer of metal lies between each pair of bricks.

FIGURE 11 shows in a schematic form an arrangement for encasing bricksaccording to the present invention. Basic brick 10 is placed on asuitable conveyor with its side face 11 hearing two shallow depressions12, and case 13 is placed on brick 10 so that its edge 26 overliesdepressions 12. The brick and casing then pass to the pressing stationwhere hydraulic or air pressure is applied by means of rams 25 to deformthe casing as at 16 into conformity with the shape of about one-half ofdepression 12. Where the case is to be heat deformed, there can beemployed the spot-welding devicewith copper, water-cooled electrodesdescribed above, or ram devices can be employed which are heated, e.g.by electrical resistance, and which can be operated by air, steam orhydraulic pressure. When metal is to be deformed into the depression, itis frequently advantageous to apply heat in order to effect suchdeformation of metal more rapidly and with less strain to the metal. Inthe arrangement of FIG. 11, if a second U-shaped casing is to beapplied, the brick is turned over, another casing applied to theuncoated side and the brick and casing forwarded to the depressingstation as previously described.

FIGURE 12 shows schematically an' arrangement for encasing brickaccording to the present invention when a metal button is employed. Inthis arrangement there is provided a basic refractory brick 10 havingdepressions 12 in one side face thereof and in the next stage as thebrick moves along a conveyor belt of any suitable construction,

metal buttons 17 are placed in depressions 12, suitably with the use ofa small amount of adhesive (not shown). Then metal casings, of theordinary U-shape as at 13 and 13', are placed on brick 10 in such mannerthat their edges lie adjacent each other and are disposed over the metalbuttons 17. The bricks and casings then go to the Welding station wheretwo resistant welding electrodes are disposed at the same distance apartas depressions 12. The brick 10 and casings 13 are held firmly by abacking block 27 which may be maintained under pressure hydraulically orotherwise as indicated schematically at 28. The welding devices 29 arethen moved into contact with the edges of the metal casings 13 and 13'and metal buttons 17 and welding heat is applied to weld the casingstogether while the metal of the button 17 melts, joining cases 13 and13, and after solidification, keying the cases securely to brick 10. Theedges of cases 13 and 13 will also be slightly depressed into shallowdepressions 12 under the influence ,of the heat and pressure of thewelding devices. It will be understood that, if desired, casings 13 canbe held firmly against the brick during the depressing and/ or weldingoperations illustrated in FIGURES 11 and 12, by a top pressure block(not shown).

It is an advantage of the present invention that metal casings can beapplied to many shapes of brick with secure affixation to the brick sothat the casings do not fall off during subsequent handling andinstallation, thereby preventing both breakage of the brick and injuriesto workmen. It is a specific advantage that the brick is not weakenedbecause metal does not extend deeply into the brick. The shallowdepressions, which are preferably from about /2 to one inch in diameter,are found to be of sufficient extent that when metal is pressed downinto conformity with these depressions the casing is effectivelyprevented from springing away from the brick or from moving or slippingabout on the brick, and, furthermore, the depressions assist in handlingthe brick by giving convenient thumb or finger holds to the workmen. Itis a further advantage of the present invention that casings can be moresecurely aflixed to a preformed brick which can be either burned orchemically bonded, that is, not burned. In applying metal cases topreformed bricks in the past, it has been proposed to punch a smallportion of the metal into the brick so that a tang of metal extendsdownwardly into the brick material and securely aifixes the case to thebrick. However, this often results in zones of weakness or even hairlinecracks which develop into larger cracks upon heating in the furnace andresult in spalling or excessive breakage of the brick; and it is aspecial advantage of the present process that the shallow depressionsare preformed or drilled into the brick without production of such zonesof weakness or cracks, and the metal which is deformed into suchdepressions exerts suflicient fiictional force to maintain the brick andthe casing in secure contact. By means of deformation into thedepressions which are shallow and discontinuous, the casing is preventedfrom moving substantially in any direction.

In the above specific description, Where heat has been applied to thecasing, the use of welding devices therefor has been described, but itwill be understood that, alternatively, there can be employed otherlocalized heating, for example, by an oxy-acetylene flame or by otherdesired means. Also, such heating elements, with added pressure means ifnecessary, can be disposed at both sides of the brick if desired todepress metal into the brick on both faces and into one or preferablytwo preformed depressions, as described, in the brick. In heating toeffect deformation or depression of the metal, it has been foundsuitable in practice to heat to cherry red when working with steelplate, but a suitable degree of heat can be readily selected by theoperator. The after-heating to temper, or post-heating, is effected inthe manner well known in the welding art, i.e at somewhat lesstemperature than the deforming heating and for a short time. Thepreformed depression can be formed in the brick at the time of pressing,and this is an expeditious and economical procedure in general. However,the depressions can also be preformed by drilling or grinding a hole ofthe desired size in the brick after formation, as described above, afterwhich the metal casing is applied as described herein. The casingaffixed to a refractory brick or block according to the presentinvention extends over at least two surfaces of such brick and ispreferably a U-shaped, or channel, casing. The adhesive, which isemployed if desired to hold the metal button in place during forwardingto the welding station, is preferably a combustible adhesive such as asticky, rubbery adhesive of the type of rubber latex, artificial rubberlatex, vinyl resin latex or the like, which burns upon heating or firingto form essentially carbon dioxide and water and therefore does not,upon installation and use in a furnace,

deleteriously affect the strength or other characteristics of therefractory component, even locally. It will be understood that adhesivecan also be applied between the brick and casing if desired.

Having now described the invention, what is claimed is:

1. The method of applying a metal casing to a nonacid refractory brickwhich comprises forming in said brick at least one shallow discontinuousdepression in a longitudinal face, placing on said brick a U-shapedmetal casing composed of a web and two arms, said casing being disposedover three longitudinal faces of said brick such that one of said armsis disposed above said depression, applying heat to said casing abovesaid shallow depression, and pressing and locally deforming said metalcasing into said shallow depression while heating.

2. Method of applying a metal casing to a basic refractory brick whichcomprises pressing said brick with at least one shallow discontinuousdepression in at least one side face of said brick, placing on saidbrick a U- shaped casing, the web covering a major portion of one sideface of said brick and arms extending over adjacent side faces, one armlying above said shallow depression, heating said metal above saidshallow depression and pressing and locally deforming the heated metalinto conformity with said depression.

3. Method of applying a metal casing to a basic refractory brick whichcomprises providing said brick with at least two shallow discontinuousdepressions in one longitudinal face thereof, placing on said brick a U-shaped casing, the web covering a major portion of one side face of saidbrick and arms extending over adjacent side faces, one arm lying abovesaid shallow depressions, heating said metal above said shallowdepressions and pressing and locally deforming said heated metal intoconformity with said depressions.

4. Method as in claim 3 wherein said metal after depressing is heated totemper and relieve stresses.

5. Method of applying a metal casing to a basicrefractory brick whichcomprises providing said brick with two shallow discontinuousdepressionsin a longitudinal face thereof, said shallow depressions being disposedin a line parallel with a longitudinal edge of said brick, placing onsaid brick two U-shaped casings, said U-shaped casings having edgesabutting above said shallow depressions, heating said metal above saidshallow depressions and pressing and locally deforming said heated metalinto conformity with said depressions, and continuing to heat said metalto temper and relieve stresses.

6. Method of applying a metal casing to a basic refractory brick whichcomprises providing said brick with at least one shallow discontinuousdepression in a longitudinal face thereof, placing two U-shaped casingson said brick in opposed relationship and such that the edges of opposedarms of said U-shaped casings are disposed adjacent each other abovesaid shallow depression, placing a metal button in contact with theedges of said two U-shaped casings above said depression, and applyingpressure and welding heat to weld said cases and said button and depressmetal into said shallow depressions.

7. Method of applying a metal casing to a basic refractory brick whichcomprises providing said brick with at least one shallow discontinuousdepression in a longitudinal face thereof during formation of saidbrick, placing a metal button in said depression, placing on said bricktwo U-shaped casings in opposed relationship and such that the edges ofopposed arms of said U-shaped casings are disposed adjacent each otherin a common plane above said shallow depression and said button,applying pressure and welding heat to weld said casings to said buttonand depress said edges into said shallow depression.

8. Method of applying a metal casing to a basic refractory brick whichcomprises providing said brick with at least one shallow discontinuousdepression in a longitudinal face thereof during formation of saidbrick, placing in said shallow depression a metal button conforming tothe shape of said depression and fitting flush with said face of saidbrick, placing on said brick two U- shaped casings in opposedrelationship, such that the edges of opposed arms of said U-shapedcasings are disposed adjacent each other in a common plane above saidshallow depression and said button, and welding said casings and saidbutton together.

9. Method of applying a metal casing to a basic re.- fractory brickwhich comprises providing said brick with at least one shallowdiscontinuous depression in a longitudinal face thereof, adhesivelyaffixing a metal button in said depression, placing two U-shaped casingson said brick in opposed relationship, such that the edges of opposedarms of said U-shaped casings are disposed adjacent each other in acommon plane above said shallow depression and button, and welding saidcasings and button.

10. Method of applying a metal casing to a basic refractory brick whichcomp-rises providing said brick with at least one shallow discontinuousdepression in a longitudinal face thereof, placing on said brick twoU-shaped casings in opposed relationship such that the edges of opposedarms of said U-shaped casings are disposed adjacent each other abovesaid shallow depression, placing a metal button over said casings abovesaid depression, and applying pressure and welding heat to Weld saidcasings together and depress said metal into said depression.

11. Method of applying a metal plating to a nonacid refractory brickwhich comprises providing said brick with at least one shallow,discontinuous depression in each of two longitudinal sides thereof,placing two ferrous metal U-shaped cases upon said brick in opposedrelation, such that opposing edges of the arms of said cases aredisposed adjacent each above each of said depressions, placing a ferrousmetal button in contact with the edges of said casings above each saiddepression, welding said cases and said buttons together at each saiddepression, and pressing and deforming said button and edges into eachsaid depression.

12. Method of applying a metal casing to a nonacid refractory brickwhich comprises forming in a longitudinal face of said brick during thepressing thereof at least one shallow discontinuous rounded depression,placing two U-shaped casings on said brick in opposed relation such thatthe edges of opposing arms of said cases are disposed adjacent eachother above said depression, heating said metal cases above saiddepression and pressing and locally deforming said metal into saiddepression.

13. Method as in claim 12 wherein after depressing metal into saiddepression, said metal is heated to temper and relieve stresses.

14. Method of applying a metal casing to a nonacid refractory brickwhich comprises forming in at least one side face of said brick at leastone shallow discontinuous depression contained wholly within said face,placing on said brick a U-shaped casing, the web of said casing coveringa major portion of one side face of said brick and the arms of saidcasing extending over adjacent side faces thereof, the edge of at leastone said, arm lying above said shallow depression, and then applyinglocalized pressure to the area of said edge above said depression andlocally deforming said area into conformity and frictional engagementwith the surface of said depression.

15. Method of applying a metal casing to a nonacid refractory brickhaving a first side face and a pair of adjacent side faces whichcomprises forming in a central portion of one of said pair of adjacentside faces at least one shallow discontinuous depression of diminutivearea compared to the area of said one side face and lying wholly withinsaid central portion thereof, placing on said brick a U-shaped casing,the web of said casing covering a portion of said first side face ofsaid brick and the arms of said casing extending over said pair ofadjacent side faces and with one of said arms having a portion lyingwholly over said shallow depression, and then applying localizedpressure to the portion of said arm overlying said depression andlocally deforming said portion of said arm into conformity andfrictional engagement with the surface of said depression.

16. Method of applying a metal casing to a nonacid refractory brickhaving a first side face and a pair of adjacent side faces whichcomprises forming within a centrul portion between the end edges andsubstantially midway of the side edges of one of said pair of adjacentside faces at least one shallow discontinuous depression of diminutivearea compared to the area of said one side face, placing on said brick aU-shaped casing, the web of said casing covering a portion of said firstside face of said brick and the arms of said casing extending over saidpair of adjacent side faces and with one of said arms having a portionlying wholly over said shallow depression, and then applying localizedpressure to the portion of Said arm overlying said depression andlocally deforming said portion of said arm into conformity andfrictional engagement with the surface of said depression.

17. Method of applying a metal casing to a nonacid refractory brickhaving a first side face and a pair of adjacent side faces whichcomprises forming within a central portion between the end edges andsubstantially midway of the side edges of one of said pair of adjacentside faces a pair of shallow discontinuous depressions of diminutiveareas compared to the 'area of said one side face, placing on said bricka U-shaped casing, the web of said casing covering a portion of saidfirst side face of said brick and the arms ofsoid casing extending oversaid pair of adjacent side faces and with one of said arms havingportions lying wholly over said shallow depressions, and then applyinglocalized pressure to the portions of said arm overlying saiddepressions and locally deforming said portions of said arm intoconformity and frictional engagement with the surface of saiddepression.

References Cited in the file of this patent or the original patentUNITED STATES PATENTS 1,250,971 Converse Dec. 25, 1917 1,593,297 GilrnerJuly 20, 1926 1,700,101 Smith Jan. 22, 1929 2,125,192 Morlock July 26,1938 2,125,193 Morlock July 26, 1938 2,158,759 Morlock May 16, 19392,187,669 Stewart Jan. 16, 1940 2,422,461 Arquette June 17, 19472,673,373 Heuer Mar. 30, 1954 2,682,703 Schob July 6, 1954 2,736,187Coifman et al. Feb. 28, 1956 2,791,116 Heuer May 7, 1957 FOREIGN PATENTS567,418 Great Britain Feb. 13, 1945

